1. Field Of The Invention
The present invention relates to adjustable roof support mechanisms for supporting the roofs of mines, and more particularly to the foot element(s) and the cooperating strut element(s) which form a part of such adjustable roof support mechanisms.
2. The Prior Art
Adjustable roof support mechanisms for supporting the roofs of mines are well known. See, for example, U.S. Pat. Nos. 4,056,941, 4,222,686 and 4,586,851, which disclose such mechanisms, particularly for use in coal mines. Such roof support mechanisms normally include a front shield for contacting and supporting the roof of the mine, a rear shield which is pivotally connected to the front shield, one or more foot elements which rest on the floor of the mine, a plurality of connecting arms which connect the rear end of the foot element(s) to the rear end of the rear shield, and one or more extendable strut elements which extend upwardly from the foot element(s) to the front shield (or else to a rocker arm connected between the front shield and the rear shield). The foot elements and the cooperating strut elements are often constructed such that, after the foot elements are located at the use site, the lower ends of the strut elements can be positioned therein. Side (lateral) liners are then downwardly inserted into the foot elements to prevent unintentional removal of the strut elements from the foot elements. However, inserting such side liners is a rather tedious operation.
It is an object of the present invention to provide a foot element and a cooperating strut element for use in a roof support mechanism, wherein the strut element is easily attachable to the foot element and wherein when the strut element is connected to the foot element for use, undesired separation thereof will be prevented, without the use of side liners.